The Calendar view gives you a monthly, weekly or daily snapshot of all cards due that period.
Each pipe has its own calendar and it only shows the cards from that pipe that have a due date set.
Enabling this app is easy, simply open the sidebar menu of your pipe by clicking the gear icon on the upper right corner of the screen then click on apps.
After you do, click on Calendar. This window will pop-up on your screen:
Click on the green 'Enable' button to activate the app. Once you refresh the page, the following icon will be displayed on your pipe's header:
You can access your pipe's calendar by clicking on the 'Calendar' option.
When accessing your calendar, you can choose to display all cards due: in the current month, the current week or the current day, depending on your preferences.
Check out below, I chose the option to view all cards due in the current month:
If you prefer to see all cards that were due the previous or are due next month, week or day - simply click the arrows on the left or right side of 'Today'.
If you prefer to view all cards due for the next 30 days in a list format, simply choose the 'Agenda' option:
You can also adjust the date range you wish to see by clicking the little arrows on the left and right side of 'Today'. It'll then show you all cards due X days earlier or later than today until one month from then.